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		<meta charset="UTF-8">
		<title>Reduce、Map混合使用计算时分秒</title>
	</head>
	<body>
		<h1>打开控制台查看输出结果</h1>
		<ul class="videos">
    <li data-time="5:43">
      Video 1
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    <li data-time="2:33">
      Video 2
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    <li data-time="3:45">
      Video 3
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    <li data-time="0:47">
      Video 4
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    <li data-time="5:21">
      Video 5
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    <li data-time="6:56">
      Video 6
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    <li data-time="3:46">
      Video 7
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    <li data-time="5:25">
      Video 8
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    <li data-time="3:14">
      Video 9
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    <li data-time="3:31">
      Video 10
    </li>
    <li data-time="5:59">
      Video 11
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    <li data-time="3:07">
      Video 12
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    <li data-time="11:29">
      Video 13
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    <li data-time="8:57">
      Video 14
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    <li data-time="5:49">
      Video 15
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    <li data-time="5:52">
      Video 16
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    <li data-time="5:50">
      Video 17
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    <li data-time="9:13">
      Video 18
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    <li data-time="11:51">
      Video 19
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    <li data-time="7:58">
      Video 20
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    <li data-time="4:40">
      Video 21
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    <li data-time="4:45">
      Video 22
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    <li data-time="6:46">
      Video 23
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    <li data-time="7:24">
      Video 24
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    <li data-time="7:12">
      Video 25
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    <li data-time="5:23">
      Video 26
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    <li data-time="3:34">
      Video 27
    </li>
    <li data-time="8:22">
      Video 28
    </li>
    <li data-time="5:17">
      Video 29
    </li>
    <li data-time="3:10">
      Video 30
    </li>
    <li data-time="4:43">
      Video 31
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    <li data-time="19:43">
      Video 32
    </li>
    <li data-time="0:47">
      Video 33
    </li>
    <li data-time="0:47">
      Video 34
    </li>
    <li data-time="3:14">
      Video 35
    </li>
    <li data-time="3:59">
      Video 36
    </li>
    <li data-time="2:43">
      Video 37
    </li>
    <li data-time="4:17">
      Video 38
    </li>
    <li data-time="6:56">
      Video 39
    </li>
    <li data-time="3:05">
      Video 40
    </li>
    <li data-time="2:06">
      Video 41
    </li>
    <li data-time="1:59">
      Video 42
    </li>
    <li data-time="1:49">
      Video 43
    </li>
    <li data-time="3:36">
      Video 44
    </li>
    <li data-time="7:10">
      Video 45
    </li>
    <li data-time="3:44">
      Video 46
    </li>
    <li data-time="3:44">
      Video 47
    </li>
    <li data-time="4:36">
      Video 48
    </li>
    <li data-time="3:16">
      Video 49
    </li>
    <li data-time="1:10">
      Video 50
    </li>
    <li data-time="6:10">
      Video 51
    </li>
    <li data-time="2:14">
      Video 52
    </li>
    <li data-time="3:44">
      Video 53
    </li>
    <li data-time="5:05">
      Video 54
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    <li data-time="6:03">
      Video 55
    </li>
    <li data-time="12:39">
      Video 56
    </li>
    <li data-time="1:56">
      Video 57
    </li>
    <li data-time="4:04">
      Video 58
    </li>
  </ul>
	</body>
	<script type="text/javascript">
		//方法一
		//获取整个 li NodeList
		let items = document.querySelectorAll('ul li');
		// 创建一个空数组，存储所有data-time字符串
		let itemtimearray = [];
		// 通过for循环将每个li中的data.time添加到 itemtimearray 数组中
		for (let item of items) {
			itemtimearray.push(item.dataset.time);
		}

		//遍历itemtimearray数组，返回一个新的数组
		let spiltimes = itemtimearray.map(item => {
			// 通过 : 将字符串拆分成数组
			let temp = item.split(':');
			// 返回对象包含分和秒的对象
			return {
				min: temp[0],
				second: temp[1]
			}
		});

		// 初始化分和秒
		let totalMin = 0;
		let totalSec = 0;
		// 通过reduce函数将spiltimes数组中所有的min叠加并存储到totalMin中
		totalMin = spiltimes.reduce((total, time) => {
			return total += parseInt(time.min);
		}, 0);
		// 通过reduce函数将spiltimes数组中所有的sec叠加并存储到totalSec中
		totalSec = spiltimes.reduce((total, time) => {
			return total += parseInt(time.second);
		}, 0);

		// 求余计算秒
		let finalSecond = parseInt(totalSec % 60);
		// 计算一共多少分钟
		let finalMin = parseInt(totalMin + (totalSec / 60)) % 60;
		// 计算一共多少小时
		let finalHour = parseInt((totalMin + (totalSec / 60)) / 60);
		// 输出时分秒
		console.log(`方法一:共${finalHour}小时,${finalMin}分钟,${finalSecond}秒.`);


		// 方法二
		// 获取所有的带data-time属性的节点
		const timeNodes = Array.from(document.querySelectorAll('[data-time'));

		const seconds = timeNodes
			// 返回一个包含所有data-time值得数组
			.map(node => node.dataset.time)
			// 返回一个将data-time解析成秒的数组
			.map(timeCode => {
				// timeCode为 1：43 这样格式的字符串
				// timeCode.aplit(':') 返回一个新数组，数组里面装的是分和秒的时间
				// [].map(parseFloat) => [].map(function(x) {return parseFloat(x)});
				const [mins, secs] = timeCode.split(':').map(parseFloat);
				// 将分乘以60+秒、计算所有的秒，并返回
				return (mins * 60) + secs;
			})
			// 将数组中的所有的秒叠加并返回
			.reduce((total, vidSeconds) => total + vidSeconds, 0);

			// 通过求余取整计算时分秒
			let secondsLeft = seconds;
			const hours = Math.floor(secondsLeft / 3600);
			secondsLeft %= 3600;

			const mins = Math.floor(secondsLeft / 60);
			secondsLeft %= 60;

			// 打印输出
			console.log(hours, mins, secondsLeft);

	</script>
</html>
